The present invention relates to a control device for a transmission having a clutch unit for a commercial vehicle, including a transmission actuator for mechanically actuating the transmission and a clutch actuator for the fluidic actuation of a clutch unit.
The main area of application of the present invention is commercial (utility) vehicle manufacturing. A central feature of many transmissions of commercial vehicles, in particular of commercial vehicles for local and distribution transport, long-distance transport and also for overland and coach transport, is the group architecture with a plurality of gears. This architecture is increasingly used for automated manual transmissions (AMT) in commercial vehicles.
Transmissions for commercial vehicles may, in principle, have different levels of automation. In this instance, actuating the clutch and selecting the gear may be carried out in an automated manner, depending on the design of the start-up procedure. None of these processes are automated for a manual transmissions; for semi-automated transmissions, one of the processes is automated; and; for the fully automated transmission of interest here, all processes are automated. Hence, there is needed a suitable actuating device for an automated starting clutch, for an automated operating of a clutch when shifting gears and for an automated gear selection and engine management.
In a generally known manner, automated clutch operation and automated gear switching are enabled by using different power elements in the form of, for example, electropneumatic or electrohydraulic actuators. Within the framework of generally known automated transmissions, clutch actuators and transmission actuators are used, which are situated in or at the transmission.
A respective actuation device is, for example, disclosed in German publication DE 100 02 693 A1.
The object of the present invention is to further develop a generic actuating device in such a manner that, in the sense of a modular design, several different transmission variations of a common transmission family are able to be controlled by a largely equivalent actuating device.
This and other objects are achieved by a control device for a transmission having at least three shift actuators for gear selection, a plurality of valves for actuating the shift actuators and a further plurality of valves for actuating the clutch. The shift actuators, the valves for actuating the shift actuators and the valves for actuating the clutch are combined in a common housing. Within this housing, the shift actuators are grouped into a spatially connected shift group, the valves are grouped into a spatially connected valve group and the clutch valves are grouped into a further spatially connected valve group. The shift group and the two valve groups do not spatially overlap.
Within the framework of the present invention, a control device for a transmission has been developed. This control device includes at least three shift actuators for the gear selection, a plurality of valves for actuating the shift actuators and a further plurality of valves for actuating the clutch.
The valves are electrically actuated via a control device and release a defined fluidic volume flow as a control signal to the shift actuators and/or starting clutch. In this instance, pressurized air and hydraulic oil can substantially be named as possible fluids.
According to the present invention, the shift actuators, the valves for actuating the shift actuators and the valves for actuating the clutch are combined in a common housing, and, within this housing,                the shift actuators are grouped into a spatially connected shift group;        the valves for actuating the shift actuators are grouped into a spatially connected valve group; and        the valves for actuating the clutch are grouped into a further spatially connected valve group,and the shift group and the two valve groups do not spatially overlap one another.        
“Spatially not overlapping” is understood in the sense of the present invention in that—in reference to the figures—between elements of a group 8, 9 or 10, no element of another group 8, 9 or 10 fully or partially extends over. This is synonymous with a space between two elements of one group being always free of elements of another group.
Such design achieves that, when manufacturing different versions of the control device, the additional expense for manufacturing, which results from the differences between the versions vis-a-vis manufacturing only one version, is minimized. Furthermore, it becomes possible to retroactively upgrade an existing control device by installing additional shift actuators and/or valves.
Thus, it is possible by this design to combine the advantages, relevant to construction space and installation, of functional integration within a closed assembly with the commercial merits of a modular architecture for covering different target applications.
Particularly advantageous embodiments of the present invention include:                the shift group is formed by identically constructed shift actuators; and/or        the valve group for actuating the shift actuators is formed by identically constructed valves; and/or        the valve group for controlling the clutch is formed by identically constructed valves.        
Then, starting from a standard version of the control device, which only includes a minimum of shift actuators and valves, further versions of the control device may be derived by taking advantage of as many constant components as possible. Ideally, the additional manufacturing expense for expanding the assembly by at least one additional shift actuator 6, inclusive of the respective expansions of valve system 8 for actuating the shift actuators, and/or for expanding valve system 9 for actuating a further starting clutch, may be substantially reduced so that a respective, specific actuating variant of housing components 2 of the standard version is manufactured.
Additional components not included in the standard version, for example, piston elements of a further cylinder and/or further valves 8g, 8h for actuating the shift actuators or valves 9e, 9f, 9g, 9h for controlling the clutch, in this instance, represent an assembly variant. Further, within the framework of a specific assembly variant, components included in the standard version may be omitted. This, for example, could be valves of valve group 8 for controlling the shift actuators or valves of valve group 9 for controlling the clutch. By dividing the space according to the present invention within housing 2 into functional groups 10, 8 and 9, all assembly modifications may be carried out independently from one another and do not affect one another.
In a further particularly advantageous embodiment of the present invention, the installation space within housing 2 provided for shift group 10 includes an expansion space 10a for receiving at least one additional shift actuator 6. In a further particularly advantageous embodiment of the present invention, the installation space within housing 2 provided for valve group 8 includes an expansion space 81 for receiving at least one additional valve 8g, 8h. In a further particularly advantageous embodiment of the present invention, the installation space within housing 2 provided for valve group 9 includes an expansion space 91 for receiving at least one additional valve 9e, 9f, 9g, 9h. These embodiments share the advantage that the assembly modifications may be carried out in a particularly simple manner. In particular, a housing 2 having identical dimensions, which respectively is only assembled in a different manner, may be used for a plurality of versions of control device 1, for example, having a different number of electrical, mechanical, pneumatic or hydraulic implementations.
In this instance, the standard version, as well as versions derived from the standard version according to the present invention, may have further characteristics or include further functions and elements in the sense of advantageous embodiments.
For this reason, the included shift actuators 3, 4, 5, 6, 7 are situated axially parallel to enable an actuation of the interior shift elements in the transmission free of transverse forces.
Further, in order to synchronize shafts present in the transmission, it may be necessary to actuate a shaft brake integrated for this purpose in the transmission. Valve device 200 necessary for this purpose may be advantageously integrated into control device 1.
For detecting and/or validating the position, the shift actuators may be advantageously provided with linear position transducers 35, 45, 55.
For packaging reasons, it may be appropriate that one or a plurality of speed sensors 300 for determining the shaft speed in the transmission are integrated into the assembly of control device 1.
In order to maximize the constant components, it is appropriate to recycle a transmission control electronics from an existing component set for electronically actuating control device 1. Then, it may be the case that shift group 10, valve group 8 for actuating the shift actuators and/or valve group 9 for controlling the clutch in total require more power for actuating the (magnetic) valves than the control electronics is able to provide. In order to make control device 1 compatible with a class of control electronics as broad as possible, at least one current amplifying electronic power output stage 100 is hence provided for shift group 10, for valve group 8 and/or for valve group 9.
In an advantageous embodiment of the present invention, valve group 9 for actuating the clutch actuator is designed to actuate one or a plurality of external clutch actuators, which have an axis offset to the gear shaft, or of a single or multiple central release bearing. In particular, valve group 9 may be designed in a standard version of control device 1 for actuating an individual external clutch actuator or a single central release bearing; however, in an expanded version, valve group 9 may be designed for actuating two external clutch actuators or a dual central release bearing.
In the sense of a most optimal functional integration, it may be appropriate as a function of the gear architecture of the target application that at least one shift fork 34, 44, 54 of the shift forks of shift actuators 3, 4, 5 is situated within shift group 10 and, for this reason, also within housing 2.
For shift actuators 3, 4, 5, in which shift forks 34, 44, 45 are situated within housing 2 and, thus, are an immediate component of the assembly of control device 1, the bending moment acting upon the shift forks, resulting from the axis being offset between the actuating axis of the shift fork and the effective axis of the shift fork, may result in a bending of piston rods 32, 42, 52 of shift actuators 3, 4, 5. In order to reduce this bending, which may negatively affect the wear and leakage behavior of shift actuators 3, 4, 5, the shift fork (34, 44, 54) is, for this reason, in a further particularly advantageous embodiment of the present invention, axially fixed to the piston rod (32, 42, 52) of a shift actuator, and this piston rod is on both sides of the shift fork mounted axially movable against the housing (2).
Furthermore, in a further advantageous embodiment of the present invention, the degree of functional integration is further increased in that at least one additional shift actuator 7 for selecting the range group of a multi-range transmission is situated within the housing 2.
This further shift actuator 7, in particular, may be connected via a mechanical coupling point to a shift rod in the transmission. This coupling point is furthermore connected to the respective interior shift element of the transmission. Since the interior shift elements for shifting the range group are typically situated in the far back of the transmission, it appears appropriate to abstain, specifically for the additional shift actuators for selecting the range, from the integration of the shift forks and to instead provide mechanical coupling point 76 at the piston rod of this shift actuator.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.